The expanding market for motivation-based approaches to intervention demands specific knowledge of the role of expectancies and motivations in behavior engagement and behavioral consequences. Despite concerns over bidirectional influences between heavy alcohol use and risky sexual behavior among emerging adults, little research has either specified the links between individual motivations in these two domains or examined the event-level co-occurrence of these behaviors. Based on the theory of reasoned action, the current research plan is designed to improve understanding of the associations of the motivations for alcohol use and sex. Data will consist of web-based self-reports from college freshmen collected across 14 consecutive days. Intensive daily data allows investigation of event-level associations of behaviors and their consequences, including the modeling of within-person effects (e.g., whether an individual is more likely to have sex on days he has been drinking) which will supplement existing literature which has largely relied on variable-centered, cross-sectional data. Specific aims are: (a) to identify groups of individuals with characteristic profiles of motivations for and against drinking and sexual behavior using cluster analysis; and (b) to assess daily fluctuations and co-variations in alcohol and sexual behavior consequences based on sex-related alcohol expectancies using multi-level modeling. It is important to understand both how individuals' motivations may be similar or different for drinking and sex and how thteir positive and negative conseuqences may or may not vary together within-people across days. As motivations based on positive and negative consequences of drinking and sex are better understood, it will become clearer whether these behaviors could be targeted together in motivation-based brief interventions designed to promote public health by reducing the harm associated with alcohol use (e.g., injury, alcohol poisoning) and sexual behavior (e.g., STDs, unwanted pregnancy) on college campuses. [unreadable] [unreadable] [unreadable] [unreadable]